OpenGD77

I've had several requests about increasing the DMR speaker level, and potentially dynamically controlling its level,

I've looked in the data sheet, (thanks to Colin G4EML for extracting the details of the control registers from the data sheet on the C6000) and the DMR line output control appears to have settings from 0dB to 6dB and is normally set to 2dB, because this is the value used by the official firmware.

However, I have tried changing the line output to 6dB, and I think it may be making the audio a bit louder.

Its hard to do a objective test, without running 2 GD-77's connected to an oscilloscope, but it definitely doesn't sound any worse than before.

Note.
This version also uses the 1 DMR frame delay in the audio, as from feedback from yesterday's experimental version the 1 frame delay seems to improve the audio quality

Thanks - I did a quick test and it seems to help

Ron

n7rde wrote: ↑

Thu Jan 16, 2020 3:19 am

Thanks - I did a quick test and it seems to help

Ron

Hi Ron,

OK.

Its a bit hard to tell, but in theory the sound should be 4dB louder, i.e just over x times as much signal level, but I know the human ear's audio response is non-linear, so 4dB will not be much of an increase.

I thought the fact the GD77 sounded quieter than I remembered was just me but the change to +6db works really well. Many thanks
Ian

DJ0HF wrote: ↑

Thu Jan 16, 2020 9:36 am

I thought the fact the GD77 sounded quieter than I remembered was just me but the change to +6db works really well. Many thanks
Ian

Can you also try the latest version.

https://www.opengd77.com/viewtopic.php? ... 85c2887e71

It has this change and some other optimisations, but some people reported a problem with the 'latest'

Have tried the Latest version and it works fine on my GD77 in both FM and DMR modes and changing the Beep level to 0db or -3db doesn't cause any problems at all here, which I think some people may have reported.
Ian

Ok...

Changes to volume only affect DMR as the audio path is completely different to the FM audio

VK3KYY wrote: ↑

Thu Jan 16, 2020 10:47 am

Ok...

Changes to volume only affect DMR as the audio path is completely different to the FM audio

Okay, I only use the GD77 on DMR so I only quickly checked that FM was also still working with the latest firmware just to be on the safe side.
Ian

Hello,

Can you tell me where to: "However, I have tried changing the line output to 6dB, and I think it may be making the audio a bit louder." Where can this be changed?

OMG! Necromancer! Don't raise the dead. Leave this thread rest in peace.